Method of Robust Transmit (Tx) Processing for Radio Frequency Coexistence Management in Dual-SIM-Dual-Active communication Devices

ABSTRACT

The various embodiments include a dual-SIM-dual-active (DSDA) device and methods for implementing robust transmit (Tx) processing to resolve radio frequency coexistence interference between two subscriptions operating on the DSDA device. The DSDA device may detect when one subscription (the “aggressor”) de-senses the other subscription (the “victim”) as a result of the aggressor&#39;s transmissions, and in response, implement robust Tx processing to mitigate the effects of de-sense on the victim.

RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application No. 61/759,373 entitled “Method of Robust Rx/Tx Processing for RF Coexistence Management in Dual-SIM-Dual-Active” filed Jan. 31, 2013, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Some new designs of mobile communication devices-such as smart phones, tablet computers, and laptop computers-support two Subscriber Identity Module (SIM) cards that provide users with access to two separate mobile telephony networks. Examples of mobile telephony networks include GSM, TDSCDMA, CDMA2000, and WCDMA. Example multi-SIM mobile communication devices include mobile phones, laptop computers, smart phones, and other mobile communication devices that are enable to connect to multiple mobile telephony networks. A mobile communication device that includes two SIM cards and connects to two separate mobile telephony networks using two separate radio frequency (RF) communication circuits is termed a “dual-SIM-dual-active” (DSDA) device.

Because a DSDA device has two separate RF communication circuits or “RF chains,” each subscription on the DSDA device may use its associated RF chain to communicate with its mobile network at any time. However, because of the proximity of the antennas of the two RF chains included in a DSDA communication device, the simultaneous use of the two RF chains may cause one RF chain to desensitize and thus interfere with the ability of the other RF chain to receive transmission.

Receiver desensitization (“de-sense”), or degradation of receiver sensitivity, may result from noise interference from a nearby transmitter. In particular, when two radios are close together with one transmitting on the uplink and the other receiving on the downlink, the feedback from the transmitter may be picked by the receiver. As a result, the received signals may become corrupted and difficult or impossible to decode. Further, feedback from the transmitter can be detected by a power monitor that measures the receive signal, which would cause the mobile device to falsely determine the presence of a cell site. In particular, receiver de-sense may present a challenge in multi-radio devices, such as devices configured with multiple SIMs, due to the necessary proximity of transmitter and receiver.

In general, mobile device radio receivers may have filters to reduce interference from a simultaneous transmit signal. In order to be effective, a transmit filter needs to be positioned in the radio circuitry after the signal is amplified, but that requires a filter that can handle high power levels, and such filters are expensive. As such, previous communication system designs are inadequate to mitigate the effects of de-sense in DSDA devices. Thus, there is a need for a method for managing the de-sense received on one of the RF chains in a DSDA device.

SUMMARY

The various embodiments include a dual-SIM-dual-active device (i.e., a “DSDA” device) and methods for implementing robust Tx processing to resolve RF co-existence interference between two subscriptions operating on the DSDA device. In the various embodiments, one subscription (i.e., the aggressor communication activity or the “aggressor”) may de-sense the other subscription (the victim communication activity or the “victim”) as a result of the aggressor's transmissions, thereby negatively impacting the ability of the victim to perform reception. The DSDA device may detect this de-sensing and implement robust Tx processing to mitigate the effects of de-sense on the victim while causing minimal impact to the aggressor, thereby dramatically improving the victim's overall performance.

In an embodiment, the DSDA device may determine whether the aggressor is de-sensing the victim. The DSDA device may monitor various potential sources of interference and measure the total interference power affecting the victim. In a further embodiment, the DSDA device may determine whether the total interference power is above a certain de-sense threshold before performing further operations.

In another embodiment, the DSDA device may create an RF co-existence management strategy based on, for example, the radio access technologies of the aggressor and victim. In an embodiment, the RF co-existence management strategy may include configuring the aggressor to perform robust Tx processing such that the aggressor proactively stops, suspends, or delays uplink transmissions for a certain amount of time. The DSDA device may make such a configuration when the DSDA device determines that the victim is performing various reception activities of the victim, including, for example, RF and automatic gain control (AGC) warm-up and serving cell acquisition when coming out of discontinuous reception sleep.

In further embodiments, when creating an RF co-existence management strategy, the DSDA device may configure the aggressor to perform robust Tx processing on a certain number of the victim's downlink slots. The DSDA device may also configure the victim so as to limit the number of consecutive downlink slots that are protected by robust Tx processing and/or configure the victim to implement throttling during robust Tx processing during the victim's idle frame.

In an embodiment, the DSDA device may determine whether to implement robust Tx processing. For example, the DSDA device may determine whether implementing robust Tx processing is too costly. The DSDA device's assessment may be based on the extent to which the aggressor's Tx power and/or data throughput would be affected by robust Tx processing and/or the relative priorities of the victim and aggressor.

In further embodiments, the DSDA device may implement robust Tx processing on the aggressor. In an embodiment, the DSDA device may configure the aggressor to reduce its transmitter's gain during the victim's downlink slots. In another embodiment, the DSDA may configure the aggressor perform operations such as ignoring uplink/reverse-link transmit power control (TPC) commands. The DSDA may continue to implement robust Tx processing for a determined duration (i.e., until a detected RF interference event is over) and may configure the victim and aggressor to operate normally when the DSDA device is not implementing robust Tx processing.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the features of the invention.

FIG. 1 is a communication system block diagram of a network suitable for use with the various embodiments.

FIG. 2 is a component block diagram of an embodiment dual-SIM dual active wireless communications device.

FIG. 3 is a component block diagram illustrating the interaction between components of different transmit/receive chains in an embodiment dual-SIM dual active wireless communications device.

FIG. 4 is a process flow diagram illustrating an embodiment method for implementing an RF co-existence strategy on a DSDA device.

FIG. 5 is a process flow diagram illustrating an embodiment method for determining whether a victim is de-sensed above a de-sense threshold.

FIG. 6 is a process flow diagram illustrating an embodiment method for creating an RF co-existence management strategy.

FIGS. 7A-7B are process flow diagrams illustrating embodiment methods for configuring implementations of robust Tx processing.

FIGS. 8A-8B are embodiment look-up tables used when configuring implementations of robust Tx processing.

FIG. 9 is a component diagram illustrating an RF interference event.

FIG. 10 is a process flow diagram illustrating an embodiment method for implementing robust Tx processing.

FIG. 11 is a component diagram of an example DSDA device suitable for use with the various embodiments.

DETAILED DESCRIPTION

The various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims.

As used herein, the term “DSDA device” refers to any one or all of cellular telephones, smart phones, personal or mobile multi-media players, personal data assistants, laptop computers, personal computers, tablet computers, smart books, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, wireless gaming controllers, and similar personal electronic devices which include a programmable processor and memory and circuitry for connecting to at least two mobile communication networks. The various aspects may be useful in mobile communication devices, such as smart phones, and so such devices are referred to in the descriptions of the various embodiments. However, the embodiments may be useful in any electronic devices that may individually maintain a plurality of subscriptions to a plurality of mobile networks through multiple radio communication circuits.

DSDA devices include two SIM cards that enable a user to connect to two different mobile networks (or different accounts on the same network) while using the same DSDA device. Each SIM card serves to identify and authenticate a subscriber using a particular DSDA device, and each SIM card is associated with only one subscription. For example, a SIM card may be associated with a subscription to one of GSM, TDSCDMA, CDMA2000, and WCDMA. In the various embodiments, DSDA devices may also include a plurality of RF resources (e.g., two RF chains) so that each network communications supported by both SIMs can be accomplished simultaneously if interference problems are managed.

DSDA devices can suffer from interference between two communications being accomplished simultaneously, such as when one communication session is transmitting (“Tx”) at the same time as another RF chain is attempting to receive (“Rx”). As used herein, the term “RF interference event” refers to an occasion in which one subscription in a DSDA device is attempting to transmit while the other subscription in the DSDA is attempt to receive transmission simultaneously. As used herein, the term “victim” refers to the subscription attempting to receive during a RF interference event. Additionally, the term “aggressor” refers to the subscription in the DSDA device attempting to transmit. In various embodiments, an aggressor's transmissions may de-sense the victim's reception. In other words, the victim may receive the aggressor's transmissions, which act as noise and may interfere with the victim's ability to receive wanted signals.

In DSDA devices, an aggressor's transmissions may cause severe impairment to the victim's ability to receive transmission. This interference may be in the form of blocking interference, harmonics, intermodulation, and other noises and distortion. Such interference may significantly degrade the victim's receiver sensitivity, voice call quality and data throughput. The interference may also cause higher rates for call drops and radio link failures, and cause the victim to lose a data connection. These effects may result in a reduced network capacity.

The various embodiments address this interference problem by providing methods for implementing robust Tx processing, thereby mitigating the effects of de-sense on the victim and allowing simultaneous calls on dual-SIMS without new hardware. In the various embodiments, robust Tx processing may improve the performance of the victim, thereby allowing similar performance on the victim as in a single-SIM scenario, which may be especially desirable when the victim's call has priority. Robust Tx processing may also improve the victim's performance in terms of receiver sensitivity, call setup success rate, retention rate, voice quality and data throughput, and the victim's network capacity may also be improved.

The various embodiments may be implemented within a variety of communication systems 100, such as at least two mobile telephony networks, an example of which is illustrated in FIG. 1. A first mobile network 102 and a second mobile network 104 are typical mobile networks that include a plurality of cellular base stations 130 and 140. A first DSDA device 110 may be in communication with the first mobile network 102 through a cellular connection 132 to a first base station 130. The first DSDA device 110 may also be in communication with the second mobile network 104 through a cellular connection 142 to a second base station 140. The first base station 130 may be in communication with the first mobile network 102 over a connection 134. The second base station 140 may be in communication with the second mobile network 104 over a connection 144.

A second DSDA device 120 may similarly communicate with the first mobile network 102 through a cellular connection 132 to a first base station 130. The second DSDA device 120 may communicate with the second mobile network 104 through a cellular connection 142 to the second base station 140. Cellular connections 132 and 142 may be made through two-way wireless communication links, such as 4G, 3G, CDMA, TDMA, WCDMA, GSM, and other mobile telephony communication technologies.

FIG. 2 is a functional block diagram of a DSDA device 200 that is suitable for implementing the various embodiments. The DSDA device 200 may include a first SIM interface 202 a, which may receive a first identity module SIM-1 204 a that is associated with the first subscription. The DSDA device 200 may also include a second SIM interface 202 b, which may receive a second identity module SIM-2 204 b that is associated with the second subscription.

A SIM in the various embodiments may be a Universal Integrated Circuit Card (UICC) that is configured with SIM and/or USIM applications, enabling access to, for example, GSM and/or UMTS networks. The UICC may also provide storage for a phone book and other applications. Alternatively, in a CDMA network, a SIM may be a UICC removable user identity module (R-UIM) or a CDMA subscriber identity module (CSIM) on a card.

Each SIM card may have a CPU, ROM, RAM, EEPROM and I/O circuits. A SIM used in the various embodiments may contain user account information, an international mobile subscriber identity (IMSI), a set of SIM application toolkit (SAT) commands and storage space for phone book contacts. A SIM card may further store a Home Public-Land-Mobile-Network (HPLMN) code to indicate the SIM card network operator provider. An Integrated Circuit Card Identity (ICCID) SIM serial number is printed on the SIM card for identification.

Each DSDA device 200 may include at least one controller, such as a general processor 206, which may be coupled to a coder/decoder (CODEC) 208. The CODEC 208 may in turn be coupled to a speaker 210 and a microphone 212. The general processor 206 may also be coupled to at least one memory 214. Memory 214 may be a non-transitory tangible computer readable storage medium that stores processor-executable instructions. For example, the instructions may include routing communication data relating to the first or second subscription though a corresponding baseband -RF resource chain.

The memory 214 may store operating system (OS), as well as user application software and executable instructions. The memory 214 may also store application data, such as an array data structure.

The general processor 206 and memory 214 may each be coupled to at least one baseband modem processor 216. Each SIM in the DSDA device 200 (e.g., SIM-1 202 a and SIM-2 202 b) may be associated with a baseband-RF resource chain. Each baseband-RF resource chain may include baseband modem processor 216 to perform baseband/modem functions for communications on a SIM, and one or more amplifiers and radios, referred to generally herein as RF resources 218. In one embodiment, baseband-RF resource chains may share a common baseband modem processor 216 (i.e., a single device that performs baseband/modem functions for all SIMs on the wireless device). Alternatively, each baseband-RF resource chain may include physically or logically separate baseband processors (e.g., BB1, BB2).

RF resources 218 a, 218 b may each be communication circuits or transceivers that perform transmit/receive functions for the associated SIM of the wireless device. RF resources 218 a, 218 b may be communication circuits that include separate transmit and receive circuitry, or may include a transceiver that combines transmitter and receiver functions. The RF resources 218 a, 218 b may be coupled to a wireless antenna (e.g., a first wireless antenna 220 a and a second wireless antenna 220 b). The RF resources 218 a, 218 b may also be coupled to the baseband modem processor 216.

In a particular embodiment, the general processor 206, memory 214, baseband processor(s) 216, and RF resources 218 a, 218 b may be included in the DSDA device 200 as a system-on-chip. In another embodiment, the first and second SIMs 202 a, 202 b and their corresponding interfaces 204 a, 204 b may be external to the system-on-chip. Further, various input and output devices may be coupled to components on the system-on-chip, such as interfaces or controllers. Example user input components suitable for use in the DSDA device 200 may include, but are not limited to, a keypad 224 and a touchscreen display 226.

In an embodiment, the keypad 224, touchscreen display 226, microphone 212, or a combination thereof, may perform the function of receiving the request to initiate an outgoing call. For example, the touchscreen display 226 may receive a selection of a contact from a contact list or receive a telephone number. In another example, either or both of the touchscreen display 226 and microphone 212 may perform the function of receiving a request to initiate an outgoing call. For example, the touchscreen display 226 may receive selection of a contact from a contact list or to receive a telephone number. As another example, the request to initiate the outgoing call may be in the form of a voice command received via the microphone 212. Interfaces may be provided between the various software modules and functions in DSDA device 200 to enable communication between them, as is known in the art.

FIG. 3 illustrates a block diagram 300 of transmit and receive components in separate RF resources. For example, a transmitter 302 may be part of one RF resource 218 a, and a receiver 304 may be part of another RF resource 218 b, as described above with reference to FIG. 2. In a particular embodiment, the transmitter 302 may include a data processor 306 that may format, encode, and interleave data to be transmitted. The transmitter 302 may include a modulator 308 that modulates a carrier signal with encoded data, for example, by performing Gaussian minimum shift keying (GMSK). One or more transmit circuits 310 may condition the modulated signal (e.g., by filtering, amplifying, and upconverting) to generate a RF modulated signal for transmission. The RF modulated signal may be transmitted, for example, to a base station 130 via an antenna, such as antenna 220 a as shown in FIG. 2.

At the receiver 304, an antenna 220 b may receive RF modulated signals from a base station 140 for example. However, the antenna 220 b may also receive some RF signaling from the transmitter 302, which ultimately competes with the desired signal from the base station 140. One or more receive circuits 316 may condition (e.g., filter, amplify, and downconvert) the received RF modulated signal, digitize the conditioned signal, and provide samples to a demodulator 318. The demodulator 318 may extract the original information-bearing signal from the modulated carrier wave, and may provide the demodulated signal to a data processor 320. The data processor 320 may de-interleave and decode the signal to obtain the original, decoded data, and may provide decoded data to other components in the wireless device. Operations of the transmitter and the receiver may be controlled by a processor, such as a baseband processor(s) 216 as illustrated in FIG. 2. In the various embodiments, each of the transmitter 302 and receiver 304 may be implemented as circuitry that may be separated from their corresponding receive and transmit circuitries (not shown). Alternatively, the transmitter 302 and the receiver 304 may be respectively combined with corresponding receive circuitry and transmit circuitry (i.e., as transceivers associated with SIM-1 and SIM-2).

As discussed above, receiver de-sense may occur when data associated with a first SIM transmitted on the uplink interferes with receive activity on a different transmit/receive chain that may be associated with a second SIM. The desired signals may become corrupted and difficult or impossible to decode. Further, noise from the transmitter may be detected by a power monitor that measures the signal strength of surrounding cells, which may cause the DSDA device to falsely determine the presence of a nearby cell site.

In an embodiment, upon detecting that receiver de-sense may occur due to interference from transmit signals associated with another SIM in a DSDA device, the DSDA device may implement an algorithm to select an optimal de-sense mitigating action, such as robust Tx processing. In an embodiment, and as further discussed in reference to FIG. 10 below, implementing robust Tx processing may include reducing the aggressor's transmitter's gain.

By tailoring the mitigating action to various properties of the transmitter and receiver, the DSDA device may maximize reduction in de-sense on the victim while minimizing possible degradation of service. The mitigating actions may be taken as soon as de-sense is detected without waiting for a response from the affected network.

FIG. 4 illustrates an embodiment DSDA device method 400 for using robust Tx processing to mitigate the effects of de-sense on a victim. In block 402, the DSDA device may determine the radio access technology identities of the victim and the aggressor. For example, the DSDA device may determine that the victim is a subscription using an frequency-division duplexing technology (“FDD”), such as WCDMA or CDMA, and that the aggressor is a subscription using time-divisional duplexing technology (“TDD”), such as a GSM radio technology.

In block 404, the DSDA device may monitor for an RF interference event affecting the victim. In various embodiments, an RF interference event may include a situation in which the aggressor's transmitter de-senses the victim's receiver. For example, the aggressor may attempt to transmit while the victim is attempting to receive.

In determination block 406, the DSDA device may determine whether an RF interference event is detected. For example, the DSDA device may determine whether the aggressor is de-sensing the victim in excess of an acceptable threshold level of de-sense. In various embodiments, the DSDA device may also assess whether the magnitude of the victim's de-sense is sufficient to merit implementing an RF co-existence management strategy. In other words, the DSDA device may determine whether the degree of de-sense exceeds a cost threshold (i.e. is “worth” the costs) associated with implementing an RF co-existence management strategy.

If the DSDA device determines that an RF interference event is not detected (i.e., determination block 406=“No”), this process may continue in a loop as the DSDA device may continue monitoring for an RF interference event in block 404.

Otherwise, if the DSDA device determines that an RF interference event is detected (i.e., determination block 406=“Yes”), the DSDA device may create an RF co-existence management strategy based on various factors in block 408. In various embodiments, the DSDA device may utilize a RF co-existence management strategy to mitigate the effects of the aggressor's de-sensing the victim. For example, the RF co-existence management strategy may call for the change of characteristics or configurations of one or both of the victim and the aggressor during the aggressor's transmissions, such as by implementing robust Tx processing.

In an embodiment, the DSDA device may consider various factors when creating an RF co-existence management strategy, including: the identities and priorities of the victim and aggressor, the priorities of the signals the victim receives versus the signals the aggressor transmits, and the relative costs of implementing robust Tx processing on the aggressor or implementing robust Rx processing on the victim. For example, the DSDA device may consider how implementing robust Tx processing may affect the aggressor's transmission power. Several embodiments of creating an RF co-existence management strategy based on various factors are discussed in further detail below with reference to FIGS. 6, 7A, and 7B.

In an embodiment, the DSDA device may ultimately determine whether to implement robust Tx processing at the aggressor as part of the DSDA device's RF co-existence management strategy. For example, the DSDA device may determine to implement robust Tx processing at the aggressor rather than doing nothing or implementing robust Rx processing at the victim (e.g., configuring the victim to ignore certain transmissions during the aggressor's transmissions). If the DSDA device determines not to implement robust Tx processing as part of the RF co-existence management strategy (i.e., determination block 414=“No”), the process may continue in a loop as the DSDA device may continue monitoring for an RF interference event in block 404. In an embodiment, the DSDA device may not implement robust Tx processing, for example, in a situation in which the aggressor needs to transmit a critical message and the victim is of lower priority and could tolerate the de-sense for a short period of time.

If the DSDA device determines to implement robust Tx processing as part of the RF co-existence management strategy (i.e., determination block 414=“Yes”), the DSDA device may optionally determine in optional determination block 416 whether the de-sense is intermodulation de-sense. If the DSDA determines that the de-sense is intermodulation de-sense (i.e., optional determination block 416=“Yes”), the DSDA device may implement robust Tx processing on the victim based on the determined RF co-existence management strategy in optional block 420. The DSDA device may also continue performing by determining whether the RF interference event is persisting in determination block 422.

If the DSDA device determines that the de-sense is not intermodulation de-sense (i.e., optional determination block 416=“No”), the DSDA device may implement robust Tx processing on the aggressor based on the determined RF co-existence management strategy in block 418. In various embodiments, robust Tx processing may include configuring the aggressor to reduce its transmitter gain. In another embodiment, the aggressor may reduce its transmitter's gain so that the gain is “zeroed out” (i.e., the aggressor's transmitter does not transmit at all). Operations involved in robust Tx processing are discussed below in detail in regards to FIG. 10.

In determination block 422, the DSDA device may determine whether the RF interference event is persisting. In other words, the DSDA device may determine whether the circumstances that created the RF interference event are ongoing. For example, the DSDA device may determine whether the aggressor is continuing to de-sense the victim during an ongoing schedule of Tx bursts.

If the DSDA device determines that the RF interference event is persisting (i.e., determination block 422=“Yes”), the DSDA device may continue implementing the RF co-existence management strategy in block 424. For example, the DSDA device may continue to implement robust Tx processing until the RF interference event has concluded. This process may continue in a loop as the DSDA device may continue performing in determination block 422 until the DSDA device determines that the RF interference event is not persisting.

If the DSDA device determines that the RF interference event is not persisting (i.e., determination block 422=“No”), the DSDA device may return the victim and aggressor to normal operations. In other words, once the RF interference event has concluded (i.e., when the de-sensing situation has ended), the DSDA device may revert the victim and aggressor to normal operations. In an embodiment, in block 426, the DSDA device may discontinue implementing robust Tx processing on the aggressor. In another embodiment, the DSDA device may reinitialize one or more aspects of the victim and/or aggressor after implementing robust Tx processing. In an example, the DSDA device may configure the aggressor to cease zeroing out its transmitter's gain when robust Tx processing is terminated. This process may continue in a loop as the DSDA device may continue monitoring for another RF interference event in block 404.

FIG. 5 illustrates an embodiment DSDA device method 500 for determining whether an RF interference event has occurred. The operations of method 500 implement an embodiment of the operations of blocks 404 and 406 of method 400 described above with reference to FIG. 4.

In various embodiments, the DSDA device may monitor various RF aspects associated with each of the two subscriptions included in the DSDA device to determine whether an RF interference event is occurring. In an embodiment, the DSDA device may determine whether an RF interference event is occurring based on various RF measurements and threshold checks, for example, by monitoring one or more sources of interference.

In an embodiment, the DSDA device may monitor the combination of the antenna, band, channel, and transmitter power for the aggressor in block 502. In further embodiments, the DSDA device may monitor various gains and other electrical features regarding the two subscriptions.

In block 508, the DSDA device may monitor the receiver power for the victim. The DSDA device may additionally determine the number of interference mechanisms that exist at a given time in block 512.

In block 514, the DSDA device may calculate (or estimate) the total amount of interference power based on direction and the number of de-sense mechanisms in each direction. In an embodiment, the DSDA device's calculation may produce a value that signifies the total interference that may be affecting the receiver. In block 516, the DSDA device may compare that total interference power to the receiver power of the victim. The DSDA device may also determine in determination block 518 whether the total interference power is over a de-sense threshold value. In an embodiment, the de-sense threshold value may indicate the point at which the total interference power affecting the victim is “non-negligible.” In other words, total interference powers that exceed the de-sense threshold value may substantially affect the performance of the victim such that implementing an RF co-existence management strategy would benefit the performance of at least one of the victim and the aggressor. On the other hand, a total interference power that does not exceed the de-sense threshold value may not affect the victim enough to warrant implementation of an RF co-existence management strategy because of the costs of implementing such a strategy.

In an embodiment, an RF interference event may be indicated when the total interference power exceeds a de-sense threshold. Thus, if the DSDA device determines the total interference power exceed a de-sense threshold (i.e., determination block 518=“Yes”), the DSDA device may continue operating by creating an RF co-existence management strategy in block 408 of method 400 described above with reference to FIG. 4. Otherwise, the DSDA device may continue operating by monitoring for an RF interference event in block 404 of method 400 described above with reference to FIG. 4. In other words, when determination block 518=“No,” the total power interference may not be sufficient to cause the DSDA device to create or implement an RF co-existence management strategy because the costs of implementing such a strategy would outweigh any benefits of implementation.

FIG. 6 illustrates an embodiment DSDA device method 600 for creating an RF co-existence management strategy. The operations of method 600 implement an embodiment of the operations of blocks 408 and 414 of method 400 described above with reference to FIG. 4. In an embodiment, the DSDA device may begin performing method 600 after determining that an RF interference event is detected (i.e., determination block 406=“Yes”). In another embodiment, the DSDA device may perform method 600 when the aggressor utilizes a WCDMA or CDMA radio technology.

In block 632, the DSDA device may determine the aggressor's transmission power increase cost that is required to implement robust Tx processing. In the various embodiments, robust Tx processing may incur a cost on the link-level performance of the technology being blanked (e.g., WCDMA/CDMA), and, therefore, the DSDA device may assess whether the costs of robust Tx processing are greater than the benefit of invoking robust Tx processing. In an embodiment, robust Tx processing may increase the power needed for the aggressor to close the uplink/reverse link. For example, the aggressor may have to increase its transmitter power in direct proportion to the amount of robust Tx processing that the DSDA device implements. Thus, the amount of degradation for the aggressor's transmitter goes up as the duration of robust Tx processing increases.

In block 634, the DSDA device may also determine a priority for each of the aggressor and the victim. The aggressor and victim's respective priorities may be established in various ways. In an embodiment, the DSDA device may base priority on the type of data that the victim and the aggressor are respectively handling. For example, the victim may have a higher priority when receiving voice than the aggressor does when transmitting data.

In determination block 636, the DSDA device may determine whether the required increase in the aggressor's transmission power is too high and whether the aggressor has a higher priority than the victim. In other words, the DSDA device may determine whether the cost of implementing robust Tx processing are too high and whether the aggressor has a high enough priority to avoid robust Tx processing. If the DSDA device determines that the aggressor's priority is higher than the victim and that the cost of increasing the aggressor's transmission power is too high (i.e., determination block 636=“Yes”), the DSDA device may not implement robust Tx processing as part of the RF co-existence strategy in block 638. In an embodiment, if the DSDA device determines not to implement robust Tx processing, there may be no de-sense mitigation implemented as part of the RF co-existence management strategy, and the victim may be subject to de-sensing. In that event, this process may continue in a loop as the DSDA device may continue monitoring for an RF interference event affecting a victim in block 404 of method 400 described above with reference to FIG. 4.

On the other hand, if the DSDA device determines that the aggressor's transmission power is not too high or that the aggressor does not have a higher priority than the victim (i.e., determination block 636=“No”), the DSDA device may configure the victim and aggressor for implementation of robust Tx processing as part of the RF co-existence strategy in block 640. In an embodiment, the DSDA device may configure various aspects of the victim and/or the aggressor before implementing robust Tx processing. Embodiment methods of configuring the victim and/or the aggressor are discussed in detail below with reference to FIGS. 7A and 7B.

The DSDA may continue performing by implementing the robust Tx processing on the aggressor in block 418 of method 400 described above with reference to FIG. 4.

FIG. 7A illustrates an embodiment DSDA device method 640 a for configuring the victim and the aggressor for implementation of robust Tx blanking. The operations of method 640 a implement an embodiment of the operations of block 640 of method 600 described above with reference to FIG. 6. In an embodiment, the DSDA device may perform method 640 a when the victim uses an FDD radio technology and the aggressor uses a TDD radio technology. For example, the victim may be WCDMA/CDMA and the aggressor may be GSM or TDMA. In another embodiment, the DSDA device may perform method 640 a when the victim is in traffic, accessing, or idle. The DSDA device may begin performing method 640 a after determining that implementing robust Tx blanking would not increase in the aggressor's transmission power too much or that the aggressor's priority is higher than the victim's priority (i.e., determination block 636=“No”).

In block 704, the DSDA device may notify the aggressor of the victim's start time for RF and automatic gain control (AGC) warm-up, serving cell acquisition, paging decode, and neighbor searches. In an embodiment, the victim may have a higher priority than the aggressor during certain critical times in which the victim's need to receive outweighs the aggressor's need to transmit. The timings for the various items indicated in block 704 may indicate such critical times.

The DSDA device may also determine whether the victim is performing one or more reception activities that are sensitive to RF interference. For example, in determination block 706, the DSDA device may determine whether the victim is performing RF and AGC warm-up and serving cell acquisition coming out of discontinuous reception sleep. In an embodiment, the victim may idle and periodically “wake-up” to receive paging messages from a network (i.e., perform discontinuous reception). If the victim is performing RF and AGC warm-up and serving cell acquisition coming out of discontinuous reception sleep (i.e., determination block 706=“Yes”), in block 714, the DSDA device may configure the aggressor to perform robust Tx processing such that the aggressor proactively stops, suspends, or delays uplink transmissions for a certain amount of time. In an embodiment, the DSDA device may configure the aggressor to stop transmitting for a certain time to allow the victim to receive paging messages from the victim's network.

If the victim is not performing RF and AGC warm-up and serving cell acquisition coming out of discontinuous reception sleep (i.e., determination block 706=“No”), the DSDA device may determine in determination block 708 whether the victim is performing AGC acquisition and a search on a neighbor cell. In an embodiment, the DSDA device may perform various searches depending on the victim's radio technology, such as another frequency search and a candidate frequency search when the victim's radio technology is 1x/EV-DO. If the victim is performing AGC acquisition and a search on a neighbor cell (i.e., determination block 708=“Yes”), in block 714, the DSDA device may configure the aggressor to perform robust Tx processing such that the aggressor proactively stops, suspends, or delays uplink transmission for a certain amount of time. In an embodiment, the aggressor may stop, suspend, or delay uplink transmission for a certain amount of time to enable the victim to complete the entire search. In another embodiment, the aggressor may stop, suspend, or delay uplink transmission only during the victim's AGC acquisition and RF tuning, and the victim may schedule its searches around the aggressor's Tx bursts. Otherwise, if the victim is not performing AGC acquisition and a search on a neighbor cell (i.e., determination block 708=“No”), the DSDA device may determine in determination block 710 whether the victim is performing AGC acquisition and compressed mode gaps.

If the victim is performing AGC acquisition in compressed mode gaps (i.e., determination block 710=“Yes”), the DSDA device may configure the aggressor to perform robust Tx processing such that the aggressor proactively stops, suspends, or delays uplink transmission for a certain time in block 714. In an embodiment, the victim may perform searches around the aggressor's Tx bursts when the aggressor uses WCDMA radio technology. Otherwise (i.e., determination block 710=“No”), the DSDA device may schedule the victim to perform searches between the aggressor's uplink slots in block 712. The DSDA device may also continue performing by implementing robust Tx processing on the aggressor in block 418 as described above with reference to FIG. 4.

FIG. 7B illustrates another embodiment DSDA device method 640 b for configuring the victim and the aggressor for implementation of robust Tx blanking. The operations of method 640 b implement an embodiment of the operations of block 640 of method 600 described above with reference to FIG. 6. In an embodiment, the DSDA device may have determined in block 402 in method 400 described with reference to FIG. 4 that the aggressor uses FDD technology (e.g., WCDMA/CDMA) and that the victim uses TDD technology (e.g., GSM).

In block 738, the DSDA device may configure the victim to have a restriction or no restriction on its multi-slot capability on the downlink. The DSDA device may also configure the aggressor to perform robust Tx processing on no more than two or three consecutive victim downlink slots (e.g., GSM downlink slots) in block 739. In a further embodiment, the remaining downlink slots may be de-sensed by the aggressor's transmission, and the DSDA device may configure the victim to respond to that transmission through protocol or signaling.

In block 740, the DSDA device may select the number of consecutive victim downlink slots to be protected by robust Tx processing as illustrated in table 800 in FIG. 8A. In an embodiment, the DSDA device may make a determination of how many slots for which type of switching technology will be protected by robust Tx processing based on the victim's priority.

For example, when the victim has a higher priority than the aggressor and is receiving via circuit switching (i.e., “CS” or voice), the DSDA device may configure the aggressor to perform robust Tx processing for two consecutive downlink slots of the victim, one for voice and another for power monitoring. In another example, when the victim has a lower priority than the aggressor and is receiving voice, the DSDA device may configure the aggressor to perform robust Tx processing on two consecutive downlink slots of the victim, one for voice and another for power monitoring. In yet another example in which the victim has a higher priority than the aggressor and is receiving via packet switching (i.e., “PS” or data), the DSDA device may configure the aggressor to perform robust Tx processing on two consecutive downlink slots of the victim, one for data and another for either data or power monitoring. In another example in which the victim has a lower priority than the aggressor and is receiving data, the DSDA device may configure the aggressor to perform robust Tx processing on two consecutive downlink slots of the victim: one for data and a GSM uplink state flag (collectively, “PS+USF”), and another for power monitoring or PS+USF. In an example in which the victim has a higher priority than the aggressor based on the priority of voice and is receiving via dual-transfer mode, the DSDA device may configure the aggressor to perform robust Tx processing on three consecutive downlink slots of the victim: one for voice, one for PS+USF, and a one for power monitoring. In yet another example in which the victim has a lower priority than the aggressor based on the priority of voice and is receiving via dual-transfer mode, the DSDA device may configure the aggressor to perform robust Tx processing on two consecutive downlink slots of the victim. In this example, one slot may be reserved for voice while the other slot is utilized by PS+USF or power monitoring, or a slot may be reserved for PS+USF while the other slot is shared between voice and power monitoring.

Returning to FIG. 7B, in block 742, the DSDA device may configure the victim to choose which two or three consecutive downlink slots are protected by robust Tx processing when the victim has more than two or three downlink slots assigned to it. In an embodiment, if the victim is in Dual-Transfer Mode (i.e., voice and data), one of the “protected” downlink slot may be for voice.

In block 744, the DSDA device may determine whether to configure the victim to implement throttling during robust Tx processing that occurs during the victim's idle frame for FCCH and SCH acquisitions. In an embodiment, the DSDA device may make this determination by performing a table lookup of table 850 in FIG. 8B. The DSDA device may throttle the victim to increase or preserve the performance of the aggressor. In a further example, the DSDA device may take into account the victim's priority relative to the aggressor's and the number of subscriptions that are active, such as whether both the aggressor and victim are both active (i.e., dual active) or if only one of the victim and the aggressor is active (i.e., single-active). In another embodiment, the DSDA device may opportunistically throttle the victim.

For example, as illustrated in table 850 in FIG. 8B, the DSDA device may not throttle the victim when the victim has a higher priority than the aggressor and only the victim is active. In another example, the DSDA device may not throttle the victim when the victim has a higher priority than the aggressor and when both the victim and aggressor are active (i.e., dual active). In an embodiment, rather than not throttling the victim in this example, the DSDA device may instead throttle the victim slightly. In yet another example in which the victim and aggressor are dual active and the victim's priority is lower than the aggressor's priority, the DSDA device may perform more than slight throttling, or significant throttling up to ½ or ⅓.

Returning to FIG. 7B, the DSDA device may also continue performing by implementing robust Tx processing on the aggressor in block 418 of method 400 described above with reference to FIG. 4.

FIG. 9 illustrates an embodiment component diagram 960 describing an example of robust Tx processing. In various embodiments, robust Tx processing may be implemented to enable a victim 964 to receive when an aggressor 962 would otherwise be transmitting and thereby de-sensing the victim 964. In an embodiment, during an RF interference event 994 in which an aggressor 962 and a victim are attempting to transmit and receive, respectively, simultaneous, the DSDA device may implement robust Tx processing to ensure that the victim 964 is able to receive without being de-sensed, thereby improving performance.

In an example robust Tx processing scenario, during a period of time in which the victim 964 is receiving (e.g., receiver periods 980 a and 980 b), the DSDA device may configure the aggressor 962 to institute robust Tx processing (i.e., robust Tx processing periods 970 a and 970 b) during these receiver periods 980 a and 980 b. Similarly, during periods in which the victim 964 is not receiving (e.g., non-receiver periods 982 a and 982 b), the aggressor 962 may transmit normally during corresponding periods of normal transmission 972 a and 972 b.

FIG. 10 illustrates an embodiment DSDA device method 418 a of implementing robust Tx processing. In various embodiments, the DSDA device may implement robust Tx processing without performing channel avoidance. The DSDA device may begin method 418 a by transitioning from determination block 414 when the DSDA device determines to implement robust Tx processing.

In determination block 1004, the DSDA device may determine whether the robust Tx processing period has started. If the period has not started (i.e., determination block 1004=“No”), the DSDA device may continue operating in determination block 1004. If the period has started (i.e., determination block 1004=“Yes”), the DSDA device may determine the duration of the robust Tx processing in block 1006.

The DSDA device may also prepare a transmission in block 1008. In an embodiment, the aggressor may have various transmissions ready for transmission. The DSDA device may determine in determination block 1010 whether the aggressor's transmission is critical. If the transmission is critical (i.e., determination block 1010=Yes”), the DSDA device may transmit the aggressor's transmission in block 1012. In other words, the DSDA device may transmit the aggressor's transmission without reducing the aggressor's transmitter's gain during the victim's DL slots. The DSDA device may continue operating in determination block 1022.

Otherwise, (i.e., determination block 1010=“No”), the DSDA device may reduce the aggressor's transmitter's gain during the victim's downlink slots in block 1014. Reducing the aggressor's transmitter's gain during the downlink slots of the victim may include zeroing out the aggressor's transmitter's gain (i.e., reducing the transmitter's gain to zero). In one example, the aggressor's transmissions may be “punctured” during the victim's downlink slots. In other words, the aggressor may transmit the prepared transmission but may dynamically reduce (or zero) its gain during the victim's downlink slots, thereby accommodating both the aggressor's transmissions and reducing the de-sense affecting the victim's reception.

In another embodiment, the DSDA device may implement various aspects of RF co-existence management strategies as discussed with relation to block 408 in FIG. 4 and FIGS. 7A-7B to affect the manner in which the aggressor's transmitter's gain is reduced during the victim's downlink slots. For example, as discussed in relation to block 739 in FIG. 7B, the DSDA device may reduce the aggressor's transmitter's gain for no more than two or three consecutive downlink slots.

The DSDA device may also determine in determination block 1016 whether the aggressor's radio access network is 1x/EV-DO. If the radio access network is 1x/EV-DO (i.e., determination block 1016=“Yes”), the DSDA device may boost the traffic-to-pilot ratio in block 1018. Otherwise (i.e., determination block 1016=“No”), the DSDA device may ignore the uplink/reverse-link TPC commands corresponding to the Tx blanked slots in block 1020. The DSDA device may continue operating in determination block 1022.

In determination block 1022, the DSDA device may determine whether the robust Tx processing duration is over. If the robust Tx processing duration is not over (i.e., determination block 1022=“No”), the process may continue as the DSDA device may continue preparing a transmission in block 1008 as described above. Otherwise, if the robust Tx processing duration is over (i.e., determination block 1022=“Yes”), the DSDA device may continue the aggressor's normal operations in block 1024. In an embodiment, continuing the aggressor's normal operations may include ceasing to reduce or zero out the aggressor's transmitter gain, thereby allowing the aggressor to transmit prepared transmission without “puncturing” the transmissions.

The DSDA device may also determine in determination block 422 whether the RF interference event is persisting. In an embodiment, the RF interference event may be persisting because the aggressor is continuing to attempt to transmit while the victim is attempting to receive. In that event, the DSDA device may continue to implement robust Tx processing. Thus, if the RF interference event is persisting (i.e., determination block 422=“Yes”), the process may continue in a loop as the DSDA device may continue determining whether a robust Tx processing period has started in determination block 1004. Otherwise, if the RF interference event is not persisting (i.e., determination block 422=“No”), the DSDA device may return the victim and aggressor to normal operations in block 426. For instance, the aggressor may stop performing robust Tx processing. In that event, the DSDA device may continue operating by monitoring for another RF interference event in block 404 of method 400 described above with reference to FIG. 4.

The various embodiments may be implemented in any of a variety of DSDA devices, an example of which is illustrated in FIG. 11. For example, the DSDA device 1100 may include a processor 1102 coupled to internal memory 1104. Internal memory 1104 may be volatile or non-volatile memory, and may also be secure and/or encrypted memory, or unsecure and/or unencrypted memory, or any combination thereof. The processor 1102 may also be coupled to a touch screen display 1106, such as a resistive-sensing touch screen, capacitive-sensing touch screen infrared sensing touch screen, or the like. Additionally, the display of the DSDA device 1100 need not have touch screen capability. Additionally, the DSDA device 1100 may have one or more antenna 1108 for sending and receiving electromagnetic radiation that may be connected to a wireless data link and/or cellular telephone transceiver 1116 coupled to the processor 1102. The DSDA device 1100 may also include physical buttons 1112 a and 1112 b for receiving user inputs. The DSDA device 1100 may also include a power button 1118 for turning the DSDA device 1100 on and off. The DSDA device 1100 may have a first SIM card 1120 that utilize a cellular telephone transceiver 1116 and one or more antennae 1108 to connect to a first mobile network. The DSDA device may also have a second SIM card 1122 that utilizes a second cellular telephone transceiver 1124 and one or more antennae 1126 to connect to a second mobile network

The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by one of skill in the art the order of steps in the foregoing embodiments may be performed in any order. Words such as “thereafter,” “then,” “next,” etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an” or “the” is not to be construed as limiting the element to the singular.

The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The hardware used to implement the various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Alternatively, some steps or methods may be performed by circuitry that is specific to a given function.

In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a non-transitory computer-readable storage medium or non-transitory processor-readable storage medium. The steps of a method or algorithm disclosed herein may be embodied in a processor-executable software module which may reside on a non-transitory computer-readable or processor-readable storage medium. Non-transitory computer-readable or processor-readable storage media may be any storage media that may be accessed by a computer or a processor. By way of example but not limitation, such non-transitory computer-readable or processor-readable storage media may include RAM, ROM, EEPROM, FLASH memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of non-transitory computer-readable and processor-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and/or instructions on a non-transitory processor-readable storage medium and/or computer-readable storage medium, which may be incorporated into a computer program product.

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein. 

What is claimed is:
 1. A method for implementing a radio frequency (RF) co-existence management strategy on a dual-SIM dual active (DSDA) device between an aggressor communication activity (an aggressor) and a victim communication activity (a victim), comprising: determining whether an RF interference event is detected; creating an RF co-existence management strategy in response to determining that an RF interference event is detected; determining whether to implement robust transmit (Tx) processing as part of the RF co-existence management strategy; and implementing the robust Tx processing on the aggressor in response to determining to implement robust Tx processing as part of the RF co-existence management strategy.
 2. The method of claim 1, further comprising: determining whether the RF interference event is persisting; returning the victim and the aggressor to normal operations in response to determining that the RF interference event is not persisting; and continuing to implement the RF co-existence management strategy in response to determining that the RF interference event is persisting.
 3. The method of claim 1, wherein determining whether an RF interference event is detected comprises: monitoring one or more sources of interference; calculating a total amount of interference power based on one or more sources of interference; determining whether the total amount of interference power exceeds a de-sense threshold; and determining that an RF interference event is detected when the total amount of interference power exceeds the de-sense threshold.
 4. The method of claim 1, wherein determining whether to implement the robust Tx processing as part of the RF co-existence management strategy comprises: determining a priority of the victim and a priority of the aggressor; determining a cost of implementing the robust Tx processing on a transmission power of the aggressor; determining whether the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds a cost threshold; determining whether the priority of the aggressor is higher than the priority of the victim; determining to implement the robust Tx processing unless it is determined that the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds the cost threshold and it is determined that the priority of the aggressor is higher than the priority of the victim; and configuring at least one of the victim and the aggressor for implementation of the robust Tx processing in response to determining to implement the robust Tx processing.
 5. The method of claim 4, wherein configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: notifying the aggressor of a start time of the victim for at least one of RF warm-up and automatic gain control (AGC) warm-up, serving cell acquisition, paging decode, and neighbor searches; determining whether the victim is performing one or more reception activities; configuring the aggressor to perform the robust Tx processing in response to determining that the victim is performing one or more reception activities, such that the aggressor proactively performs one of stopping, suspending, or delaying uplink transmission for a certain time; and scheduling the victim to perform searches between uplink slots of the aggressor in response to determining that the victim is not performing one or more reception activities.
 6. The method of claim 5, wherein the one or more reception activities comprise: performing RF and AGC warm-up and serving cell acquisition upon coming out of discontinuous reception sleep; performing AGC acquisition and a search on a neighbor cell; and performing AGC acquisition and compressed mode gaps.
 7. The method of claim 4, wherein configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: configuring the victim to have one of a restriction and no restriction on its multi-slot capability on downlink; configuring the aggressor to perform the robust Tx processing on no more than two or three consecutive downlink slots; selecting a number of consecutive victim downlink slots to be protected by the robust Tx processing; choosing on the victim which the two or three consecutive downlink slots are protected by the robust Tx processing when the victim has more than two or three downlink slots assigned; and determining whether to configure the victim to implement throttling during the robust Tx processing that occurs during an idle frame of the victim for frequency correction channels and synchronization channels.
 8. The method of claim 7, wherein selecting the number of consecutive victim downlink slots to be protected by the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a type of switching technology that the victim is using; and selecting the number of consecutive victim downlink slots based on the priority of the victim and the type of switching technology that the victim is using.
 9. The method of claim 7, wherein determining whether to configure the victim to implement throttling during the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a number of subscriptions that are currently active; and implementing throttling based on the priority of the victim and the number of subscriptions that are currently active.
 10. The method of claim 1, wherein implementing the robust Tx processing comprises reducing a gain of the aggressor's transmitter during downlink slots of the victim.
 11. The method of claim 10, further comprising: determining whether a robust Tx processing period has started; determining a duration of the robust Tx processing period in response to determining that the robust Tx processing period has started; determining whether the robust Tx processing period is over; reducing gain of the aggressor's transmitter during the downlink slots of the victim in response to determining that the robust Tx processing period is not over; and configuring the aggressor to operate normally in response to determining that the robust Tx processing period is over.
 12. The method of claim 10, wherein reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises: preparing a transmission for the aggressor; determining whether the transmission is critical; transmitting the transmission when the transmission is critical; and reducing the gain of the aggressor's transmitter during the downlink slots of the victim when the transmission is not critical.
 13. The method of claim 10, wherein reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises zeroing out the gain of the aggressor's transmitter during the downlink slots of the victim.
 14. The method of claim 10, further comprising ignoring uplink/reverse-link transmit power control commands.
 15. The method of claim 10, further comprising: determining whether a radio access network of the aggressor is 1x/EV-DO; and boosting a traffic-to-pilot ratio when the radio access network of the aggressor is 1x/EV-DO.
 16. A dual-SIM-dual-active device, comprising: a memory; a plurality of SIMs; a plurality of radio frequency (RF) resources; and a processor coupled to the memory, the plurality of SIMs, and the plurality of RF resources, wherein the processor is configured with processor-executable instructions to perform operations comprising: determining whether an RF interference event between an aggressor communication activity (an aggressor) and a victim communication activity (a victim) is detected; creating an RF co-existence management strategy in response to determining that an RF interference event is detected; determining whether to implement robust transmit (Tx) processing as part of the RF co-existence management strategy; and implementing the robust Tx processing on the aggressor in response to determining to implement robust Tx processing as part of the RF co-existence management strategy.
 17. The dual-SIM-dual-active device of claim 16, wherein the processor is configured with processor-executable instructions to perform operations further comprising: determining whether the RF interference event is persisting; returning the victim and the aggressor to normal operations in response to determining that the RF interference event is not persisting; and continuing to implement the RF co-existence management strategy in response to determining that the RF interference event is persisting.
 18. The dual-SIM-dual-active device of claim 16, wherein the processor is configured with processor-executable instructions to perform operations such that determining whether an RF interference event is detected comprises: monitoring one or more sources of interference; calculating a total amount of interference power based on one or more sources of interference; determining whether the total amount of interference power exceeds a de-sense threshold; and determining that an RF interference event is detected when the total amount of interference power exceeds the de-sense threshold.
 19. The dual-SIM-dual-active device of claim 16, wherein the processor is configured with processor-executable instructions to perform operations such that determining whether to implement the robust Tx processing as part of the RF co-existence management strategy comprises: determining a priority of the victim and a priority of the aggressor; determining a cost of implementing the robust Tx processing on a transmission power of the aggressor; determining whether the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds a cost threshold; determining whether the priority of the aggressor is higher than the priority of the victim; determining to implement the robust Tx processing unless it is determined that the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds the cost threshold and it is determined that the priority of the aggressor is higher than the priority of the victim; and configuring at least one of the victim and the aggressor for implementation of the robust Tx processing in response to determining to implement the robust Tx processing.
 20. The dual-SIM-dual-active device of claim 19, wherein the processor is configured with processor-executable instructions to perform operations such that configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: notifying the aggressor of a start time of the victim for at least one of RF warm-up and automatic gain control (AGC) warm-up, serving cell acquisition, paging decode, and neighbor searches; determining whether the victim is performing one or more reception activities; configuring the aggressor to perform the robust Tx processing in response to determining that the victim is performing one or more reception activities, such that the aggressor proactively performs one of stopping, suspending, or delaying uplink transmission for a certain time; and scheduling the victim to perform searches between uplink slots of the aggressor in response to determining that the victim is not performing one or more reception activities.
 21. The dual-SIM-dual-active device of claim 20, wherein the processor is configured with processor-executable instructions to perform operations such that the one or more reception activities comprise: performing RF and AGC warm-up and serving cell acquisition upon coming out of discontinuous reception sleep; performing AGC acquisition and a search on a neighbor cell; and performing AGC acquisition and compressed mode gaps.
 22. The dual-SIM-dual-active device of claim 19, wherein the processor is configured with processor-executable instructions to perform operations such that configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: configuring the victim to have one of a restriction and no restriction on its multi-slot capability on downlink; configuring the aggressor to perform the robust Tx processing on no more than two or three consecutive downlink slots; selecting a number of consecutive victim downlink slots to be protected by the robust Tx processing; choosing on the victim which the two or three consecutive downlink slots are protected by the robust Tx processing when the victim has more than two or three downlink slots assigned; and determining whether to configure the victim to implement throttling during the robust Tx processing that occurs during an idle frame of the victim for frequency correction channels and synchronization channels.
 23. The dual-SIM-dual-active device of claim 22, wherein the processor is configured with processor-executable instructions to perform operations such that selecting the number of consecutive victim downlink slots to be protected by the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a type of switching technology that the victim is using; and selecting the number of consecutive victim downlink slots based on the priority of the victim and the type of switching technology that the victim is using.
 24. The dual-SIM-dual-active device of claim 22, wherein the processor is configured with processor-executable instructions to perform operations such that determining whether to configure the victim to implement throttling during the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a number of subscriptions that are currently active; and implementing throttling based on the priority of the victim and the number of subscriptions that are currently active.
 25. The dual-SIM-dual-active device of claim 16, wherein the processor is configured with processor-executable instructions to perform operations such that implementing the robust Tx processing comprises reducing a gain of the aggressor's transmitter during downlink slots of the victim.
 26. The dual-SIM-dual-active device of claim 25, wherein the processor is configured with processor-executable instructions to perform operations further comprising: determining whether a robust Tx processing period has started; determining a duration of the robust Tx processing period in response to determining that the robust Tx processing period has started; determining whether the robust Tx processing period is over; reducing gain of the aggressor's transmitter during the downlink slots of the victim in response to determining that the robust Tx processing period is not over; and configuring the aggressor to operate normally in response to determining that the robust Tx processing period is over.
 27. The dual-SIM-dual-active device of claim 25, wherein the processor is configured with processor-executable instructions to perform operations such that reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises: preparing a transmission for the aggressor; determining whether the transmission is critical; transmitting the transmission when the transmission is critical; and reducing the gain of the aggressor's transmitter during the downlink slots of the victim when the transmission is not critical.
 28. The dual-SIM-dual-active device of claim 25, wherein the processor is configured with processor-executable instructions to perform operations such that reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises zeroing out the gain of the aggressor's transmitter during the downlink slots of the victim.
 29. The dual-SIM-dual-active device of claim 25, wherein the processor is configured with processor-executable instructions to perform operations further comprising ignoring uplink/reverse-link transmit power control commands.
 30. The dual-SIM-dual-active device of claim 25, wherein the processor is configured with processor-executable instructions to perform operations further comprising: determining whether a radio access network of the aggressor is 1x/EV-DO; and boosting a traffic-to-pilot ratio when the radio access network of the aggressor is 1x/EV-DO.
 31. A dual-SIM-dual-active device, comprising: means for determining whether a radio frequency (RF) interference event between an aggressor communication activity (an aggressor) and a victim communication activity (a victim) is detected; means for creating an RF co-existence management strategy in response to determining that an RF interference event is detected; means for determining whether to implement robust transmit (Tx) processing as part of the RF co-existence management strategy; and means for implementing the robust Tx processing on the aggressor in response to determining to implement robust Tx processing as part of the RF co-existence management strategy.
 32. The dual-SIM-dual-active device of claim 31, further comprising: means for determining whether the RF interference event is persisting; means for returning the victim and the aggressor to normal operations in response to determining that the RF interference event is not persisting; and means for continuing to implement the RF co-existence management strategy in response to determining that the RF interference event is persisting.
 33. The dual-SIM-dual-active device of claim 31, wherein means for determining whether an RF interference event is detected comprises: means for monitoring one or more sources of interference; means for calculating a total amount of interference power based on one or more sources of interference; means for determining whether the total amount of interference power exceeds a de-sense threshold; and means for determining that an RF interference event is detected when the total amount of interference power exceeds the de-sense threshold.
 34. The dual-SIM-dual-active device of claim 31, wherein means for determining whether to implement the robust Tx processing as part of the RF co-existence management strategy comprises: means for determining a priority of the victim and a priority of the aggressor; means for determining a cost of implementing the robust Tx processing on a transmission power of the aggressor; means for determining whether the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds a cost threshold; means for determining whether the priority of the aggressor is higher than the priority of the victim; means for determining to implement the robust Tx processing unless it is determined that the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds the cost threshold and it is determined that the priority of the aggressor is higher than the priority of the victim; and means for configuring at least one of the victim and the aggressor for implementation of the robust Tx processing in response to determining to implement the robust Tx processing.
 35. The dual-SIM-dual-active device of claim 34, wherein means for configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: means for notifying the aggressor of a start time of the victim for at least one of RF warm-up and automatic gain control (AGC) warm-up, serving cell acquisition, paging decode, and neighbor searches; means for determining whether the victim is performing one or more reception activities; means for configuring the aggressor to perform the robust Tx processing in response to determining that the victim is performing one or more reception activities, such that the aggressor proactively performs one of stopping, suspending, or delaying uplink transmission for a certain time; and means for scheduling the victim to perform searches between uplink slots of the aggressor in response to determining that the victim is not performing one or more reception activities.
 36. The dual-SIM-dual-active device of claim 35, wherein the one or more reception activities comprise: performing RF and AGC warm-up and serving cell acquisition upon coming out of discontinuous reception sleep; performing AGC acquisition and a search on a neighbor cell; and performing AGC acquisition and compressed mode gaps.
 37. The dual-SIM-dual-active device of claim 34, wherein means for configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: means for configuring the victim to have one of a restriction and no restriction on its multi-slot capability on downlink; means for configuring the aggressor to perform the robust Tx processing on no more than two or three consecutive downlink slots; means for selecting a number of consecutive victim downlink slots to be protected by the robust Tx processing; means for choosing on the victim which the two or three consecutive downlink slots are protected by the robust Tx processing when the victim has more than two or three downlink slots assigned; and means for determining whether to configure the victim to implement throttling during the robust Tx processing that occurs during an idle frame of the victim for frequency correction channels and synchronization channels.
 38. The dual-SIM-dual-active device of claim 37, wherein means for selecting the number of consecutive victim downlink slots to be protected by the robust Tx processing comprises: means for determining whether the priority of the victim is higher than the priority of the aggressor; means for determining a type of switching technology that the victim is using; and means for selecting the number of consecutive victim downlink slots based on the priority of the victim and the type of switching technology that the victim is using.
 39. The dual-SIM-dual-active device of claim 37, wherein means for determining whether to configure the victim to implement throttling during the robust Tx processing comprises: means for determining whether the priority of the victim is higher than the priority of the aggressor; means for determining a number of subscriptions that are currently active; and means for implementing throttling based on the priority of the victim and the number of subscriptions that are currently active.
 40. The dual-SIM-dual-active device of claim 31, wherein means for implementing the robust Tx processing comprises means for reducing a gain of the aggressor's transmitter during downlink slots of the victim.
 41. The dual-SIM-dual-active device of claim 40, further comprising: means for determining whether a robust Tx processing period has started; means for determining a duration of the robust Tx processing period in response to determining that the robust Tx processing period has started; means for determining whether the robust Tx processing period is over; means for reducing gain of the aggressor's transmitter during the downlink slots of the victim in response to determining that the robust Tx processing period is not over; and means for configuring the aggressor to operate normally in response to determining that the robust Tx processing period is over.
 42. The dual-SIM-dual-active device of claim 40, wherein means for reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises: means for preparing a transmission for the aggressor; means for determining whether the transmission is critical; means for transmitting the transmission when the transmission is critical; and means for reducing the gain of the aggressor's transmitter during the downlink slots of the victim when the transmission is not critical.
 43. The dual-SIM-dual-active device of claim 40, wherein means for reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises means for zeroing out the gain of the aggressor's transmitter during the downlink slots of the victim.
 44. The dual-SIM-dual-active device of claim 40, further comprising means for ignoring uplink/reverse-link transmit power control commands.
 45. The dual-SIM-dual-active device of claim 40, further comprising: means for determining whether a radio access network of the aggressor is 1x/EV-DO; and means for boosting a traffic-to-pilot ratio when the radio access network of the aggressor is 1x/EV-DO.
 46. A non-transitory processor-readable storage medium having stored thereon processor-executable software instructions configured to cause a processor of a dual-SIM-dual-active device to perform operations comprising: determining whether a radio frequency (RF) interference event between an aggressor communication activity (an aggressor) and a victim communication activity (a victim) is detected; creating an RF co-existence management strategy in response to determining that an RF interference event is detected; determining whether to implement robust transmit (Tx) processing as part of the RF co-existence management strategy; and implementing the robust Tx processing on the aggressor in response to determining to implement robust Tx processing as part of the RF co-existence management strategy.
 47. The non-transitory processor-readable storage medium of claim 46, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations further comprising: determining whether the RF interference event is persisting; returning the victim and the aggressor to normal operations in response to determining that the RF interference event is not persisting; and continuing to implement the RF co-existence management strategy in response to determining that the RF interference event is persisting.
 48. The non-transitory processor-readable storage medium of claim 46, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that determining whether an RF interference event is detected comprises: monitoring one or more sources of interference; calculating a total amount of interference power based on one or more sources of interference; determining whether the total amount of interference power exceeds a de-sense threshold; and determining that an RF interference event is detected when the total amount of interference power exceeds the de-sense threshold.
 49. The non-transitory processor-readable storage medium of claim 46, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that determining whether to implement the robust Tx processing as part of the RF co-existence management strategy comprises: determining a priority of the victim and a priority of the aggressor; determining a cost of implementing the robust Tx processing on a transmission power of the aggressor; determining whether the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds a cost threshold; determining whether the priority of the aggressor is higher than the priority of the victim; determining to implement the robust Tx processing unless it is determined that the cost of implementing the robust Tx processing on the transmission power of the aggressor exceeds the cost threshold and it is determined that the priority of the aggressor is higher than the priority of the victim; and configuring at least one of the victim and the aggressor for implementation of the robust Tx processing in response to determining to implement the robust Tx processing.
 50. The non-transitory processor-readable storage medium of claim 49, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: notifying the aggressor of a start time of the victim for at least one of RF warm-up and automatic gain control (AGC) warm-up, serving cell acquisition, paging decode, and neighbor searches; determining whether the victim is performing one or more reception activities; configuring the aggressor to perform the robust Tx processing in response to determining that the victim is performing one or more reception activities, such that the aggressor proactively performs one of stopping, suspending, or delaying uplink transmission for a certain time; and scheduling the victim to perform searches between uplink slots of the aggressor in response to determining that the victim is not performing one or more reception activities.
 51. The non-transitory processor-readable storage medium of claim 50, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that the one or more reception activities comprise: performing RF and AGC warm-up and serving cell acquisition upon coming out of discontinuous reception sleep; performing AGC acquisition and a search on a neighbor cell; and performing AGC acquisition and compressed mode gaps.
 52. The non-transitory processor-readable storage medium of claim 49, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that configuring at least one of the victim and the aggressor for implementation of the robust Tx processing comprises: configuring the victim to have one of a restriction and no restriction on its multi-slot capability on downlink; configuring the aggressor to perform the robust Tx processing on no more than two or three consecutive downlink slots; selecting a number of consecutive victim downlink slots to be protected by the robust Tx processing; choosing on the victim which the two or three consecutive downlink slots are protected by the robust Tx processing when the victim has more than two or three downlink slots assigned; and determining whether to configure the victim to implement throttling during the robust Tx processing that occurs during an idle frame of the victim for frequency correction channels and synchronization channels.
 53. The non-transitory processor-readable storage medium of claim 52, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that selecting the number of consecutive victim downlink slots to be protected by the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a type of switching technology that the victim is using; and selecting the number of consecutive victim downlink slots based on the priority of the victim and the type of switching technology that the victim is using.
 54. The non-transitory processor-readable storage medium of claim 52, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that determining whether to configure the victim to implement throttling during the robust Tx processing comprises: determining whether the priority of the victim is higher than the priority of the aggressor; determining a number of subscriptions that are currently active; and implementing throttling based on the priority of the victim and the number of subscriptions that are currently active.
 55. The non-transitory processor-readable storage medium of claim 46, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that implementing the robust Tx processing comprises reducing a gain of the aggressor's transmitter during downlink slots of the victim.
 56. The non-transitory processor-readable storage medium of claim 55, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations further comprising: determining whether a robust Tx processing period has started; determining a duration of the robust Tx processing period in response to determining that the robust Tx processing period has started; determining whether the robust Tx processing period is over; reducing gain of the aggressor's transmitter during the downlink slots of the victim in response to determining that the robust Tx processing period is not over; and configuring the aggressor to operate normally in response to determining that the robust Tx processing period is over.
 57. The non-transitory processor-readable storage medium of claim 55, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises: preparing a transmission for the aggressor; determining whether the transmission is critical; transmitting the transmission when the transmission is critical; and reducing the gain of the aggressor's transmitter during the downlink slots of the victim when the transmission is not critical.
 58. The non-transitory processor-readable storage medium of claim 55, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations such that reducing the gain of the aggressor's transmitter during the downlink slots of the victim comprises zeroing out the gain of the aggressor's transmitter during the downlink slots of the victim.
 59. The non-transitory processor-readable storage medium of claim 55, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations further comprising ignoring uplink/reverse-link transmit power control commands.
 60. The non-transitory processor-readable storage medium of claim 55, wherein the stored processor-executable software instructions are configured to cause a processor of a dual-SIM-dual-active device to perform operations further comprising: determining whether a radio access network of the aggressor is 1x/EV-DO; and boosting a traffic-to-pilot ratio when the radio access network of the aggressor is 1x/EV-DO. 